As a result of globalization and economic advancement countries like South Africa (SA) are experiencing a risk transition in which disease prevalence is shifting from being primarily infectious in nature to being primarily non-communicable in nature. This is presenting significant challenges for the health care systems of countries with scarce resources. In the U.S. evidence from large, rigorous RCT's clearly indicate that lifestyle interventions such as the Diabetes Prevention Program (DPP) can enable overweight individuals to change their diet and physical activity levels and significantly reduce their risk for diabetes mellitus (DM) and cardiovascular (CVD) diseases but the program has not been adapted for delivery in a developing word setting. The purpose of this proposal is to adapt the DPP and evaluate its feasibility and effectiveness in an urban settlement community in SA. Three initial adaptations to the DPP are proposed for this setting: (1) deliver treatment in a group format using community health workers (CHWs); (2) enhance the DPP through interactive text messaging; and (3) enhance CHW's communications skills through simplified Motivational Interviewing (MI) training. The RE-AIM model will be used to guide our intervention adaptations in order to maximize public health impact. Feasibility and effectiveness of the DPP-SA will be assessed in a real world trial using a large team of CHWs currently deployed in this community to help overweight/obese individuals with DM and/or CVD. We plan a 2 year cluster-randomized trial in which we will randomize 54 existing health clubs (N=540) to receive the DPP South Africa (DPP-SA) or usual care (wait-list). The primary outcome analysis will compare percentage of baseline weight loss at Y1 between DPP-SA and usual care; however, after Y1 usual care participants will also receive the DPP-SA and both groups will be followed for another year. This will allow us to assess whether the wait-list group's results after 1 year of treatment are similar to the original group's outcomes and examine whether the original group maintains its outcomes over 2 years. Secondary outcomes will include DM and cardiovascular risk indicators (blood pressure, hemoglobin A1C, lipids), changes in medication use, diet (fat and fruit and vegetable intake), physical activity, and health related quality of life. Feasibilityand process outcomes will be assessed among NGO staff, CHWs, and participants. We will also prepare the DPP-SA for dissemination through development of training curricula, establishing university training courses, engaging other stakeholders who are candidates for dissemination, and assessing the cost-effectiveness of the intervention with respect to cost per kg of weight loss and key secondary outcomes.